Automatic regulating system for battery operated motor-generator sets



March 7, 1939. s. s. WOLFF 2,150,112

AUTOMATIC REGULATING SYSTEM FOR BATTERY OPERATED MOTOR-GENERATOR SETS Filed April 8, 1938 zaov DC INPUT nov 60-AC OUTPUT Samuel 5 wolff Patented Mar. 7, 1939 2,150,115; ao'rom'rro anoum'rmo srs'rmu non,

BATTERY TOR SETS OPERATED A MOTOR-GENERA- Samuel s. Wolfl, Elizabeth, N. 1;, assigncr to The Singer Manufacturing Company,

Elizabet N. J., a corporation or New Jersey Application April 8, use, Serial a. realist Claims. (01. ru -12s) This invention relates to motor-generator sets and has for an object to provide an automatic regulating system therefor, whereby the motorgenerator set may be operatedfrom a direct- 5 current supply of widely variable voltage to supply an alternating current at a substantially constant frequency and voltage, suitable for ener gization of a conventional public address system. With the above and other objects'in view, as

1 will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawing of a preferred embodiment of the invention, from which the several features ofthe invention and the advantagesattained thereby will be readily understood by those skilled in the art. In the accompanying drawing, the figure represents, diagrammatically, a motor-generator set with an automatic regulating system embodying the invention.

In the preferred embodiment of the invention illustrated, M represents the motor of a motorgenerator set MG. The motor M comprises a as conventional direct current armature i with commutator brushes 2, 2, one of which is con nected by the line 3 to one terminal of the storage battery 4.

The generator G, which is self-excited, has

an armature the winding at which has the usual taps running to the commutator 5 and is also tapped at points I80 electrical degrees apart to supply the output slip rings 6. Thus the generator armature may be of the conventional type used in rotary converters but is not used as a rotary converter in the present instance. Bearing on the generator commutator 5 are the.

brushes 1, 1 across which are connected the generator shunt field winding 8 and the voltageresponsive solenoid 9 of a conventional carbom pile regulator or rheostat I0. An adjustable rheostat II is preferably connected in the generator shunt field circuit while the current in be limited, if necessary, by the resistance It.

By a suitable choice of the size of wire for the coil 9, the resistance 12 may, of course, be dispensed with.

r The regulator solenoid 9 is' arranged to attract a regulator lever l3 which is pivoted at H and exerts pressure upon the carbon pile in to lower the electrical resistance thereof. Abiasing spring it: connected to the lever l3 and having an ad- 55 justing screw it whereby its tension may be the regulator voltage-responsive solenoid 9 may regulated, is arranged to act upon the regulator lever IS in opposition to the solenoid 8.

The generator G also has a series type field winding H which is connected in the line l8 running. from the other terminal of the storage bat- 5 tery l to the other motor brush 2.

The motor has a shunt field winding i9 which is .connectedin series with the carbon-pile regulator l0 across the motor suply lines 3, i8 which are, energized by the battery i. 10

It will be understood that the storage battery will supply to the motors. direct current at a voltage which will vary over wide limits, de-- pending upon the state of charge of the battery. Notwithstanding the widely variable nature or 15 the voltage of the supply circuit, the output voltage .and frequency at the generator slip rings will remain substantially constant at various loads on the generator.

Consider, first, the circuit shown, with the 2.0 series field coil i1 not functioning. Inasmuch asthe voltage on the regulator coil 9 varies directly with the voltage at the slip rings 6, it follows that, when an output load is applied to the slip rings 8, the slip ring voltage will drop 25 dueto generator armature reaction and the regulator will weaken the motor field to speed the generator above no load speed sufflciently to maintain constant voltage at the slip rings. Thus, without the series type field coil H the 30 1 generator speed will rise with the load on the erator fleld with the load, so that the generator speed need not be increased to maintain constant 5 voltage at the slip rings but may remain substantially constant at variableoutput loads.

Thus, the regulator, in combination with the series type field coil l1, functions to maintain substantially constant voltage at substantially constant frequency at the slip rings.

The motor shunt field winding I8 is preterably so designed as to work the motor-field iron in the sensitive region below the knee of the saturation curve thereof, so that the motor field regulation will be sensitive to variations in the voltage across the brushes 1, I of the generator.

By adjusting the generator shunt field rheostat H and regulator biasing spring screw IS, the generator output voltage across the slip rings 6 may be raised or lowered, as desired, and will be held substantially constant by the present regulating system at any set output voltage, within the range provided for.

Having thus set forth the nature the invention what I claim herein is:

1. In a battery-operated motor-generator set, the combination with a storage battery, of a shunt-wound direction current motor connected to the terminals of said battery, a carbon pile regulator connected in series with the field of said motor across the terminals of said battery, said regulator having a voltage-responsive regulating ing connected in one leg of the direct current supply circuit to said motor, and means to vary solenoid and means under the influence oi said the alternating current output voltage of said 1 solenoid for compressing the carbon pile of said generator including a variable resistance in the regulator, a sell-excited alternating current gengenerator shunt held and an adjustable biasing erator driven by said motor and including an spring in said carbon pile regulator opposed to armature winding tapped to feed into a pair 0! the voltage-responsive coil of the latter.

it slip rings and a commutator, brushes bearing on 4. The combination with a storage battery and said commutator, a shunt generator fleld winding a shunt-wound motor connected to be operated connected across said brushes,thevoltage-responby said battery, of a self-excited alternating cursive solenoid of said carbon-pile regulator being rent generator driven by said motor and having also connected across said brushes, said generator alternating current and direct current output l having field windin of th s ries type terminals, a carbon pile regulator connected in 20 connected in one leg of the line between the betseries with the shunt field winding 0! said motor tery and motor. and having a voltage-responsive regulating coil 2. In a battery operated motor-generator set, connected across the direct current output termithe combination with a storage battery and a rials of said generator, said generator having a 26 shunt-wound direct current motor connected to shunt iield winding connected across the direct be energized by said battery, of a self-excited alcurrent output terminals thereof and a series type ternating current generator driven by said motor field winding connected in one leg of the battery and having an armature winding which is tapped circuit to said motor, the motor shunt fleld windfor both alternating current and direct current 118 b81118 $0 desiflned ES to W k h m r field 30 outputg, mid generator having a shunt field windiron at magnetic densities below the knee oi the 30 log connected across the direct current output saturation curve thereof. terminals thereof and a series type field winding 5. In a motor-generator set, the combination connected in one leg 01' the motor supply circuit, with a shunt-wound direct current motor, a selfand a carbon pile regulator connected in series excited alternating current generator driven by with the motor shunt field winding and having said motor, and a direct current supply circuit 35 a voltage-responsive regulating solenoid connectfor said motor, of an automatically variable rheoed across the direct current output terminals 01 stat in the shunt field or said motor, said rheosaid generator. stat having a voltage-responsive regulating coil 8. The combination with a shunt-wound motor connected to said generator, said generator havconnected to be operated by a direct current suping shunt and series type field windings, the lat- 40 ply circuit, oi a self-excited alternating current generator driven by said motor and having alternating current and direct current output termiter being energized by the direct current drawn by said motor from said supply circuit.

SAMUEL S. WOLFF.

CERTIFICATE OF CORRECTION.

Patent No. 2,150,112. March 7, 1959.

' SAMUEL S. WOLFE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second column, line 9 for "suply" read supply; page 2, first column, line 5, claim 1, for "direction" read direct; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this hth day of April, A. D. 1939;

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

